Thermodynamics and Excitation Spectrum of a Quasi-One-Dimensional Superconductor in a High Magnetic Field

TL;DR

This paper investigates the thermodynamics and excitation spectrum of high-field superconducting phases in a quasi-one-dimensional superconductor with an open Fermi surface, revealing a cascade of phases and reentrant superconductivity.

Contribution

It provides a microscopic mean-field analysis of the thermodynamics and excitation spectrum of high-field superconducting phases in quasi-1D superconductors, extending beyond Ginzburg-Landau theory.

Findings

Identification of a cascade of superconducting phases at high magnetic fields.

Observation of strong reentrance of superconductivity.

Detailed characterization of the excitation spectrum in these phases.

Abstract

At high magnetic field, the semiclassical approximation which underlies the Ginzburg-Landau theory of the mixed state of type II superconductors breaks down. In a quasi-1D superconductor with an {\it open Fermi surface}, a high magnetic field stabilizes a cascade of superconducting phases which ends in a strong reentrance of the superconducting phase. From a microscopic mean-field model, we determine the thermodynamics and the excitation spectrum of these quantum superconducting phases.